1. Field of the Invention
The present invention relates to a motorized window treatment, and more specifically, to a low-cost, quiet, battery-powered motorized window treatment that is characterized by an ultra-low power consumption that makes battery power more convenient for a user and results in long and practical battery lifetimes. In addition, the present invention relates to a battery-powered motorized window treatment that is controlled in response to wireless input signals and may be installed without requiring any additional wiring.
2. Description of the Related Art
Motorized window treatments typically include a flexible fabric or other means for covering a window in order to block or limit the daylight entering a space and to provide privacy. The motorized window treatments may comprise roller shades, cellular shades, Roman shades, Venentian blinds, and draperies. The motorized window treatments include a motor drive for movement of the fabric in front of the window to control the amount of the window that is covered by the fabric. For example, a motorized roller shade includes a flexible shade fabric wound onto an elongated roller tube with an electronic drive unit installed in the roller tube. The electronic drive unit includes a motor, such as a direct-current (DC) motor, which is operable to rotate the roller tube upon being energized by a DC voltage.
Prior art electronic drive units are typically powered directly from an AC mains line voltage (e.g., 120 VAC) or from a low-voltage DC voltage (e.g., approximately 24 VDC) provided by an external transformer. Unfortunately, this requires that electrical wires to be run from the power source to the electronic drive unit. Running additional AC main line voltage wiring to the electronic drive unit can be very expensive, due to the cost of the additional electrical wiring as well as the cost of installation. Typically, installing new AC main line voltage wiring requires a licensed electrician to perform the work. In addition, if the pre-existing wiring runs behind a fixed ceiling or wall (e.g., one comprising plaster or expensive hardwood), the electrician may need to breach the ceiling or wall to install the new electrical wiring, which will thus require subsequent repair. In some installations where low voltage (e.g., from a low-voltage DC transformer) is used to the power the electronic drive unit, the electrical wires have been mounted on an external surface of a wall or ceiling between the electronic drive unit and the transformer, which is plugged into an electrical receptacle. However, this sort of installation requires the permanent use of one of the outlets of the electrical receptacle and is aesthetically unpleasing due to the external electrical wires.
Therefore, some prior art motorized window treatments have been battery powered, such that the motorized window treatments may be installed without requiring any additional wiring. Examples of prior art battery-powered motorized window treatments are described in greater detail in U.S. Pat. No. 5,883,480, issued Mar. 16, 1999, entitled WINDOW COVERING WITH HEAD RAIL-MOUNTED ACTUATOR; U.S. Pat. No. 5,990,646, issued Nov. 23, 2009, entitled REMOTELY-CONTROLLED BATTERY POWERED-WINDOW COVERING HAVING POWER SAVING RECEIVER; and U.S. Pat. No. 7,389,806, issued Jun. 24, 2008, entitled MOTORIZED WINDOW SHADE SYSTEM.
However, the typical prior art battery-powered motorized window treatments have suffered from poor battery life (such as, one year or less), and have required batteries that are difficult and expensive to replace. Thus, there is a need for a low-cost battery-powered motorized window treatment that has longer battery life and makes battery power practical and convenient for the end user.